* [PATCH v2 0/7] Improve performance of 'faddr2line'
@ 2024-04-15 14:55 Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 1/7] scripts/faddr2line: Reduce number of readelf calls to three Brian Johannesmeyer
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
This is the second attempt at submitting this. Version 1 can be found here:
https://lore.kernel.org/lkml/20240311204019.1183634-1-bjohannesmeyer@gmail.com/.
I was looking at the performance of faddr2line and noticed that it spends
most of its time performing two tasks:
- (1) Making redundant calls to readelf and addr2line for each address
(e.g., it makes 7 readelf calls and 2 addr2line calls when converting 1
address, and it makes 252 readelf calls and 51 addr2line calls when
converting 50 addresses); and
- (2) Calculating a symbol’s size by unnecessarily looping through every
symbol in a particular section.
This patch series consists of the following parts:
- Patches 1-2 reduce the total number of readelf calls to one,
- Patches 3-4 make minor changes in preparation for the following patches,
- Patches 5-6 reduce the total number of addr2line calls to one, and
- Patch 7 modifies the symbol size calculation to only check two symbols.
I evaluated the performance of the patch series by running faddr2line with
a standard kernel image (X86_64 defconfig with CONFIG_DEBUG_INFO enabled).
When converting only 1 address, the patch series gives a negligible
speedup. When converting 50 addresses, however, it gives a 15x speedup.
Changes vs. V1:
- Correctly handle duplicate sym_names
Brian Johannesmeyer (7):
scripts/faddr2line: Reduce number of readelf calls to three
scripts/faddr2line: Combine three readelf calls into one
scripts/faddr2line: Check vmlinux only once
scripts/faddr2line: Pass --addresses argument to addr2line
scripts/faddr2line: Invoke addr2line as a single long-running process
scripts/faddr2line: Remove call to addr2line from find_dir_prefix()
scripts/faddr2line: Check only two symbols when calculating symbol
size
scripts/faddr2line | 110 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 84 insertions(+), 26 deletions(-)
--
2.34.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2 1/7] scripts/faddr2line: Reduce number of readelf calls to three
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 2/7] scripts/faddr2line: Combine three readelf calls into one Brian Johannesmeyer
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
Rather than calling readelf several times for each invocation of
__faddr2line, call readelf only three times at the beginning, and save its
result for future use.
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 587415a52b6f..bf394bfd526a 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -87,7 +87,7 @@ command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
find_dir_prefix() {
local objfile=$1
- local start_kernel_addr=$(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' |
+ local start_kernel_addr=$(echo "${ELF_SYMS}" | sed 's/\[.*\]//' |
${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
[[ -z $start_kernel_addr ]] && return
@@ -103,6 +103,14 @@ find_dir_prefix() {
return 0
}
+run_readelf() {
+ local objfile=$1
+
+ ELF_FILEHEADER=$(${READELF} --file-header $objfile)
+ ELF_SECHEADERS=$(${READELF} --section-headers --wide $objfile)
+ ELF_SYMS=$(${READELF} --symbols --wide $objfile)
+}
+
__faddr2line() {
local objfile=$1
local func_addr=$2
@@ -125,7 +133,7 @@ __faddr2line() {
# vmlinux uses absolute addresses in the section table rather than
# section offsets.
- local file_type=$(${READELF} --file-header $objfile |
+ local file_type=$(echo "${ELF_FILEHEADER}" |
${AWK} '$1 == "Type:" { print $2; exit }')
if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then
is_vmlinux=1
@@ -143,8 +151,7 @@ __faddr2line() {
local sec_name
# Get the section size:
- sec_size=$(${READELF} --section-headers --wide $objfile |
- sed 's/\[ /\[/' |
+ sec_size=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' |
${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
if [[ -z $sec_size ]]; then
@@ -154,8 +161,7 @@ __faddr2line() {
fi
# Get the section name:
- sec_name=$(${READELF} --section-headers --wide $objfile |
- sed 's/\[ /\[/' |
+ sec_name=$(echo "${ELF_SECHEADERS}" | sed 's/\[ /\[/' |
${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }')
if [[ -z $sec_name ]]; then
@@ -197,7 +203,7 @@ __faddr2line() {
found=2
break
fi
- done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
+ done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
if [[ $found = 0 ]]; then
warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
@@ -278,7 +284,7 @@ __faddr2line() {
DONE=1
- done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$8 == fn')
+ done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$8 == fn')
}
[[ $# -lt 2 ]] && usage
@@ -291,7 +297,9 @@ LIST=0
[[ ! -f $objfile ]] && die "can't find objfile $objfile"
shift
-${READELF} --section-headers --wide $objfile | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
+run_readelf $objfile
+
+echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
DIR_PREFIX=supercalifragilisticexpialidocious
find_dir_prefix $objfile
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 2/7] scripts/faddr2line: Combine three readelf calls into one
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 1/7] scripts/faddr2line: Reduce number of readelf calls to three Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 3/7] scripts/faddr2line: Check vmlinux only once Brian Johannesmeyer
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
Rather than calling readelf three separate times to collect three different
types of info, call it only once, and parse out the different types of info
from its output.
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index bf394bfd526a..f011bda4ed25 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -105,10 +105,14 @@ find_dir_prefix() {
run_readelf() {
local objfile=$1
-
- ELF_FILEHEADER=$(${READELF} --file-header $objfile)
- ELF_SECHEADERS=$(${READELF} --section-headers --wide $objfile)
- ELF_SYMS=$(${READELF} --symbols --wide $objfile)
+ local out=$(${READELF} --file-header --section-headers --symbols --wide $objfile)
+
+ # This assumes that readelf first prints the file header, then the section headers, then the symbols.
+ # Note: It seems that GNU readelf does not prefix section headers with the "There are X section headers"
+ # line when multiple options are given, so let's also match with the "Section Headers:" line.
+ ELF_FILEHEADER=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p')
+ ELF_SECHEADERS=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' | sed -n '/Symbol table .* contains [0-9]* entries:/q;p')
+ ELF_SYMS=$(echo "${out}" | sed -n '/Symbol table .* contains [0-9]* entries:/,$p')
}
__faddr2line() {
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 3/7] scripts/faddr2line: Check vmlinux only once
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 1/7] scripts/faddr2line: Reduce number of readelf calls to three Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 2/7] scripts/faddr2line: Combine three readelf calls into one Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 4/7] scripts/faddr2line: Pass --addresses argument to addr2line Brian Johannesmeyer
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
Rather than checking whether the object file is vmlinux for each invocation
of __faddr2line, check it only once beforehand.
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index f011bda4ed25..bb3b5f03f4ea 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -115,6 +115,17 @@ run_readelf() {
ELF_SYMS=$(echo "${out}" | sed -n '/Symbol table .* contains [0-9]* entries:/,$p')
}
+check_vmlinux() {
+ # vmlinux uses absolute addresses in the section table rather than
+ # section offsets.
+ IS_VMLINUX=0
+ local file_type=$(echo "${ELF_FILEHEADER}" |
+ ${AWK} '$1 == "Type:" { print $2; exit }')
+ if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then
+ IS_VMLINUX=1
+ fi
+}
+
__faddr2line() {
local objfile=$1
local func_addr=$2
@@ -125,8 +136,6 @@ __faddr2line() {
local func_offset=${func_addr#*+}
func_offset=${func_offset%/*}
local user_size=
- local file_type
- local is_vmlinux=0
[[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then
@@ -135,14 +144,6 @@ __faddr2line() {
return
fi
- # vmlinux uses absolute addresses in the section table rather than
- # section offsets.
- local file_type=$(echo "${ELF_FILEHEADER}" |
- ${AWK} '$1 == "Type:" { print $2; exit }')
- if [[ $file_type = "EXEC" ]] || [[ $file_type == "DYN" ]]; then
- is_vmlinux=1
- fi
-
# Go through each of the object's symbols which match the func name.
# In rare cases there might be duplicates, in which case we print all
# matches.
@@ -260,7 +261,7 @@ __faddr2line() {
# Pass section address to addr2line and strip absolute paths
# from the output:
local args="--functions --pretty-print --inlines --exe=$objfile"
- [[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name"
+ [[ $IS_VMLINUX = 0 ]] && args="$args --section=$sec_name"
local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;")
[[ -z $output ]] && continue
@@ -305,6 +306,8 @@ run_readelf $objfile
echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
+check_vmlinux
+
DIR_PREFIX=supercalifragilisticexpialidocious
find_dir_prefix $objfile
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 4/7] scripts/faddr2line: Pass --addresses argument to addr2line
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
` (2 preceding siblings ...)
2024-04-15 14:55 ` [PATCH v2 3/7] scripts/faddr2line: Check vmlinux only once Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 5/7] scripts/faddr2line: Invoke addr2line as a single long-running process Brian Johannesmeyer
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
In preparation for identifying an addr2line sentinel. See previous work
[0], which applies a similar change to perf.
[0] commit 8dc26b6f718a ("perf srcline: Make sentinel reading for binutils
addr2line more robust")
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index bb3b5f03f4ea..820680c59a39 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -260,9 +260,12 @@ __faddr2line() {
# Pass section address to addr2line and strip absolute paths
# from the output:
- local args="--functions --pretty-print --inlines --exe=$objfile"
+ local args="--functions --pretty-print --inlines --addresses --exe=$objfile"
[[ $IS_VMLINUX = 0 ]] && args="$args --section=$sec_name"
- local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;")
+ local output_with_addr=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;")
+ [[ -z $output_with_addr ]] && continue
+
+ local output=$(echo "${output_with_addr}" | sed 's/^0x[0-9a-fA-F]*: //')
[[ -z $output ]] && continue
# Default output (non --list):
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 5/7] scripts/faddr2line: Invoke addr2line as a single long-running process
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
` (3 preceding siblings ...)
2024-04-15 14:55 ` [PATCH v2 4/7] scripts/faddr2line: Pass --addresses argument to addr2line Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 6/7] scripts/faddr2line: Remove call to addr2line from find_dir_prefix() Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 7/7] scripts/faddr2line: Check only two symbols when calculating symbol size Brian Johannesmeyer
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
Rather than invoking a separate addr2line process for each address, invoke
a single addr2line coprocess, and pass each address to its stdin. Previous
work [0] applied a similar change to perf, leading to a ~60x speed-up [1].
If using an object file that is _not_ vmlinux, faddr2line passes a section
name argument to addr2line. Because we do not know until runtime which
section names will be passed to addr2line, we cannot apply this change to
non-vmlinux object files. Hence, it only applies to vmlinux.
[0] commit be8ecc57f180 ("perf srcline: Use long-running addr2line per
DSO")
[1] Link:
https://eighty-twenty.org/2021/09/09/perf-addr2line-speed-improvement
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 52 +++++++++++++++++++++++++++++++++++++++-------
1 file changed, 45 insertions(+), 7 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 820680c59a39..48fc8cfc80df 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -126,6 +126,48 @@ check_vmlinux() {
fi
}
+init_addr2line() {
+ local objfile=$1
+
+ check_vmlinux
+
+ ADDR2LINE_ARGS="--functions --pretty-print --inlines --addresses --exe=$objfile"
+ if [[ $IS_VMLINUX = 1 ]]; then
+ # If the executable file is vmlinux, we don't pass section names to
+ # addr2line, so we can launch it now as a single long-running process.
+ coproc ADDR2LINE_PROC (${ADDR2LINE} ${ADDR2LINE_ARGS})
+ fi
+}
+
+run_addr2line() {
+ local addr=$1
+ local sec_name=$2
+
+ if [[ $IS_VMLINUX = 1 ]]; then
+ # We send to the addr2line process: (1) the address, then (2) a sentinel
+ # value, i.e., something that can't be interpreted as a valid address
+ # (i.e., ","). This causes addr2line to write out: (1) the answer for
+ # our address, then (2) either "?? ??:0" or "0x0...0: ..." (if
+ # using binutils' addr2line), or "," (if using LLVM's addr2line).
+ echo ${addr} >& "${ADDR2LINE_PROC[1]}"
+ echo "," >& "${ADDR2LINE_PROC[1]}"
+ local first_line
+ read -r first_line <& "${ADDR2LINE_PROC[0]}"
+ ADDR2LINE_OUT=$(echo "${first_line}" | sed 's/^0x[0-9a-fA-F]*: //')
+ while read -r line <& "${ADDR2LINE_PROC[0]}"; do
+ if [[ "$line" == "?? ??:0" ]] || [[ "$line" == "," ]] || [[ $(echo "$line" | ${GREP} "^0x00*: ") ]]; then
+ break
+ fi
+ ADDR2LINE_OUT+=$'\n'$(echo "$line" | sed 's/^0x[0-9a-fA-F]*: //')
+ done
+ else
+ # Run addr2line as a single invocation.
+ local sec_arg
+ [[ -z $sec_name ]] && sec_arg="" || sec_arg="--section=${sec_name}"
+ ADDR2LINE_OUT=$(${ADDR2LINE} ${ADDR2LINE_ARGS} ${sec_arg} ${addr} | sed 's/^0x[0-9a-fA-F]*: //')
+ fi
+}
+
__faddr2line() {
local objfile=$1
local func_addr=$2
@@ -260,12 +302,8 @@ __faddr2line() {
# Pass section address to addr2line and strip absolute paths
# from the output:
- local args="--functions --pretty-print --inlines --addresses --exe=$objfile"
- [[ $IS_VMLINUX = 0 ]] && args="$args --section=$sec_name"
- local output_with_addr=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;")
- [[ -z $output_with_addr ]] && continue
-
- local output=$(echo "${output_with_addr}" | sed 's/^0x[0-9a-fA-F]*: //')
+ run_addr2line $addr $sec_name
+ local output=$(echo "${ADDR2LINE_OUT}" | sed "s; $dir_prefix\(\./\)*; ;")
[[ -z $output ]] && continue
# Default output (non --list):
@@ -309,7 +347,7 @@ run_readelf $objfile
echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO not enabled"
-check_vmlinux
+init_addr2line $objfile
DIR_PREFIX=supercalifragilisticexpialidocious
find_dir_prefix $objfile
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 6/7] scripts/faddr2line: Remove call to addr2line from find_dir_prefix()
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
` (4 preceding siblings ...)
2024-04-15 14:55 ` [PATCH v2 5/7] scripts/faddr2line: Invoke addr2line as a single long-running process Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 7/7] scripts/faddr2line: Check only two symbols when calculating symbol size Brian Johannesmeyer
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
Use the single long-running faddr2line process from find_dir_prefix().
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 48fc8cfc80df..1fa6beef9f97 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -85,15 +85,17 @@ command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
# init/main.c! This only works for vmlinux. Otherwise it falls back to
# printing the absolute path.
find_dir_prefix() {
- local objfile=$1
-
local start_kernel_addr=$(echo "${ELF_SYMS}" | sed 's/\[.*\]//' |
${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
[[ -z $start_kernel_addr ]] && return
- local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
- [[ -z $file_line ]] && return
+ run_addr2line ${start_kernel_addr} ""
+ [[ -z $ADDR2LINE_OUT ]] && return
+ local file_line=${ADDR2LINE_OUT#* at }
+ if [[ -z $file_line ]] || [[ $file_line = $ADDR2LINE_OUT ]]; then
+ return
+ fi
local prefix=${file_line%init/main.c:*}
if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
return
@@ -350,7 +352,7 @@ echo "${ELF_SECHEADERS}" | ${GREP} -q '\.debug_info' || die "CONFIG_DEBUG_INFO n
init_addr2line $objfile
DIR_PREFIX=supercalifragilisticexpialidocious
-find_dir_prefix $objfile
+find_dir_prefix
FIRST=1
while [[ $# -gt 0 ]]; do
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 7/7] scripts/faddr2line: Check only two symbols when calculating symbol size
2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
` (5 preceding siblings ...)
2024-04-15 14:55 ` [PATCH v2 6/7] scripts/faddr2line: Remove call to addr2line from find_dir_prefix() Brian Johannesmeyer
@ 2024-04-15 14:55 ` Brian Johannesmeyer
6 siblings, 0 replies; 8+ messages in thread
From: Brian Johannesmeyer @ 2024-04-15 14:55 UTC (permalink / raw
To: Josh Poimboeuf, linux-kernel, Brian Johannesmeyer
Rather than looping through each symbol in a particular section to
calculate a symbol's size, grep for the symbol and its immediate
successor, and only use those two symbols.
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
---
scripts/faddr2line | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 1fa6beef9f97..fe0cc45f03be 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -252,7 +252,7 @@ __faddr2line() {
found=2
break
fi
- done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
+ done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2 | ${GREP} -A1 --no-group-separator " ${sym_name}$")
if [[ $found = 0 ]]; then
warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
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2024-04-15 14:55 [PATCH v2 0/7] Improve performance of 'faddr2line' Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 1/7] scripts/faddr2line: Reduce number of readelf calls to three Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 2/7] scripts/faddr2line: Combine three readelf calls into one Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 3/7] scripts/faddr2line: Check vmlinux only once Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 4/7] scripts/faddr2line: Pass --addresses argument to addr2line Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 5/7] scripts/faddr2line: Invoke addr2line as a single long-running process Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 6/7] scripts/faddr2line: Remove call to addr2line from find_dir_prefix() Brian Johannesmeyer
2024-04-15 14:55 ` [PATCH v2 7/7] scripts/faddr2line: Check only two symbols when calculating symbol size Brian Johannesmeyer
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